To analysis the proportion of an element in a certain substance, the experiment could be done by gravimetric analysis and volumetric analysis, and these two methods of analysing could be occupied on several different purpose of experiments as well. In a specific experimental condition, there will be one method that is the most suitable to choose, and it is depending on the temperature, substance status, pressure and chemical properties. Here are some advantages and disadvantages about gravimetric analysis and volumetric analysis.
Gravimetric analysis has a higher accuracy, as in an experiment, the tare weight and final weight of the product will be recorded, and through the calculation, the amount could always been found, even there is a loss during the transport, and this makes the result accurate. Gravimetric analysis also does not require a strict temperature condition. Since the substances are usually solid and there is no titration performed during the experiment, temperature difference gives a small influence on gravimetric analysis, and this makes the experiment more accurate when perform in a normal experimental environment.
When having a precipitate, the precipitate must be insoluble, there is a chance that the precipitate is soluble, and once it can be solved in the solution, it would become very hard to find the final weight of the product. The final weight of the precipitate would be easily affected by any interferents left in the Gooch crucible, as after washing Gooch crucible, there might be some liquid left and then dried in the crucible, so when weight with the precipitate, the weight is heavier than the actual.
Volumetric analysis experiment usually consumes less time. Once the method could be well handled and managed, the experiment could be processed comparatively faster, since this experiment does not need to make time waiting for the precipitates, there is no section that needs to spend long time on. When doing a titration, use a burette can make the experiment very precis, as the accuracy of the equipment, it is easy to notice the colour change by using burette, and this helps finding the equivalence point very easily, so the experiment becomes accurate if well performed.
The result of a Volumetric analysis experiment usually gives a low accuracy. When transport a solution, there would always be some liquids left in the flasks, burettes and other equipments, and the amount of the solution is reduced, aftermaths, the result becomes less or more than the expected value. Volumetric analysis also has a high sensitivity of temperature. Normally, the last step of a volumetric analysis experiment would be titration, and this usually should be done under a room temperature of 25 celsius degree.
Once the temperature changes, the solubility changes, and the amount of the certain chemical needed in the experiment would be different. Therefore, temperature control is very critical to a volumetric analysis experiment, which becomes selective to the experiment condition.